Nine organic acids (citric acid, galacturonic acid, glycolic acid, isocitric acid, malic acid, oxalic acid, quinic acid, shikimic acid, and tartaric acid) and two anions (phosphate and sulfate) were determined in a suite of Vaccinium berry containing dietary supplement Standard Reference Materials (SRMs). Following solvent extraction, three independent methods were utilized in the quantification of these compounds. The first method involved reversed phase liquid chromatography with ultraviolet absorbance detection at 210 nm and isotope dilution mass spectrometry. The second method utilized ion chromatography with conductivity detection. Finally, gas chromatography with isotope dilution mass spectrometry detection was used following derivatization with N-methyl-N-trifluoroacetamide (MSTFA). The combined data from all three methods was used for the assignment of organic acid levels in the seven candidate SRMs.
Citation: Analytical and Bioanalytical Chemistry
Pub Type: Journals
Organic acids, berry, liquid chromatography, gas chromatography, ion chromatography, mass spectrometry, isotope dilution